Audi 90 1994 CS V6 2.8L Workshop Manual

audi :: Audi 90S, CS V6-2.8L (AAH) (1994)

> Relays and Modules > Relays and Modules - Brakes and Traction Control > ABS Main Relay > Component Information > Locations

ABS Main Relay: Locations

a Return flow pump relay
b Solenoid valve relay

> Relays and Modules > Relays and Modules - Brakes and Traction Control > ABS Return Flow Pump Relay <--> [Brake Fluid Pump Relay] > Component Information > Locations

ABS Return Flow Pump Relay: Locations

a Return flow pump relay
b Solenoid valve relay

> Relays and Modules > Relays and Modules - Brakes and Traction Control > ABS Solenoid Valve Relay <--> [Brake Fluid Solenoid Valve Relay] > Component Information > Locations

ABS Solenoid Valve Relay: Locations

a Return flow pump relay
b Solenoid valve relay

> Relays and Modules > Relays and Modules - Brakes and Traction Control > ABS Control Module <--> [Electronic Brake Control Module] > Component Information > Service and Repair

ABS Control Module: Service and Repair

The electronic control unit is located beneath the lefthand side of the rear seat.

1. Turn ignition switch to the Off position.

2. Remove rear seat.

3. Remove spring retaining electrical connector, then disconnect electrical connector.

4. Remove screws securing control unit.

5. Reverse procedure to install.

> Relays and Modules > Relays and Modules - Cooling System > Radiator Cooling Fan Control Module > Component Information > Diagrams > Diagram Information and Instructions > How to Use Wiring Diagrams

Radiator Cooling Fan Control Module: Diagram Information and InstructionsHow to Use Wiring Diagrams

> Relays and Modules > Relays and Modules - Cooling System > Radiator Cooling Fan Control Module > Component Information > Diagrams > Diagram Information and

Instructions > How to Use Wiring Diagrams > Page 22

90S, CS V6-2.8L (AAH) (1994)

Wiring Diagram Layout

Wiring Diagram Details

1 Arrow

Indicates wiring circuit is continued on the previous and/or next diagram section.

2 Fuse Designation

Example: S15 = Fuse number 15, 10 amps, in fuse/relay panel.

3 Test Points On Fuse/Relay Panel
4 Test Points Used During Troubleshooting

Numbers in black circles may be found in a regular wiring diagram or in a wiring diagram included with troubleshooting.

> Relays and Modules > Relays and Modules - Cooling System > Radiator Cooling Fan Control Module > Component Information > Diagrams > Diagram Information and

Instructions > How to Use Wiring Diagrams > Page 23

90S, CS V6-2.8L (AAH) (1994)

5 Wire Cross-section Size And Wire Color Code

Wire size is in mmsq, for wire size conversion to American Wire Gauge (AWG), see Wire Size Conversion Chart. Wire color codes are explained in Wire Color Code Identification.

6 Component Designation (code)

Use diagram article to identify the component code.For example: G39 = Heated Oxygen Sensor

7 Internal Connections (thin lines)

These connections are not always wires. Internal connections are current carrying and are listed to allow tracing of current flow insidecomponents and wiring harnesses.

8 Wire Harness Ground Connection

Locations of ground connections are indicated in the diagram article.

9 Relay/Control Module Connectors On Fuse/Relay Panel

Shows the individual terminals in a multi-point connector. Example: 4/304 = Contact 4 of the relay/control module socket on the relay panel or relay carrier 30 = Terminal 30 (B+) on relay/control module

10 Relay Location Number

Indicates relay location on fuse/relay panel.

11 Fuse/Relay Panel Connectors

Shows wiring of multi-point or single connectors on fuse/relay panel.Example: G1/10 = Multi-point connector G1, terminal 10

12 Terminal Designation

Designation which appears on actual component and/or terminal number of a multi-point connector.

13 Wire Continuation (Current Track Number)

Number in frame indicates current track where wire is continued.

14 Continuation of Internal Connections

Letters indicate where connection continues on the previous and/or next diagram section.

15 Component Symbols

Example component symbols are illustrated in Symbols Identification

16 Wiring Harness Splice Connection

Locations of splice connections are indicated in the diagram article.

17 Arrow

Indicates component is continued on the previous and/or next diagram section.

18 Component Designation (code) Without Component Symbol

Indicates circuit continues to a component that is on a different system diagram. The component is identified by its component designation(code).Example: J60 = Automatic Transmission RelayIf this circuit was needed it would be necessary to go to the Automatic Transmission Wiring Diagram and locate the Automatic TransmissionRelay (J60).

> Relays and Modules > Relays and Modules - Cooling System > Radiator Cooling Fan Control Module > Component Information > Diagrams > Diagram Information and Instructions > How to Use Wiring Diagrams > Page 24

Radiator Cooling Fan Control Module: Diagram Information and InstructionsWire Color Code Identification

Color Codes

WS

- White

SW

- Black

RO

- Red

BR

- Brown

GN

- Green

BL

- Blue

GR

- Gray

LI

- Violet

GE

- Yellow

OR

- Orange

Combined codes indicate a multi-colored wire.Example: The code R/G indicates a red wire with a green tracer strip.

> Relays and Modules > Relays and Modules - Cooling System > Radiator Cooling Fan Control Module > Component Information > Diagrams > Diagram Information and Instructions > How to Use Wiring Diagrams > Page 25

Radiator Cooling Fan Control Module: Diagram Information and InstructionsWire Size Conversion Chart

Wire Size

The wiring diagrams in this manual identify wires by their metric wire size. Metric wire sizes indicate cross-sectional area in square millimeter . The table below lists metric wire sizes and their equivalents in American Wire Gauge sizes.(mm sq.) (AWG)

Metric size American Wire Gauge

(mm sq.) (AWG)

0.35 22

0.5 20

0.75 18

1.0 16

1.5 14

2.5 12

4.0 10

6.0 8

16.0 4

25.0 2

35.0 2

> Relays and Modules > Relays and Modules - Cooling System > Radiator Cooling Fan Control Module > Component Information > Diagrams > Diagram Information and Instructions > How to Use Wiring Diagrams > Page 26

Radiator Cooling Fan Control Module: Diagram Information and InstructionsConnector Information

Connector Connector

Designation Type

T1 Single-point
T2 2-point
T3 3-point
T4 4-point
T6 6-point
T8 8-point
T10 10-point
T12 12-point

T26 26-point
Each connector has a unique number. Example: T6, T6a and T6b are three different 6-point connectors.
Wiring diagrams usually also identify a particular connector terminal.

3-Point Connector

Example: T3a/2 is terminal two of connector T3a.

> Relays and Modules > Relays and Modules - Cooling System > Radiator Cooling Fan Control Module > Component Information > Diagrams > Diagram Information and Instructions > How to Use Wiring Diagrams > Page 27

Radiator Cooling Fan Control Module: Diagram Information and InstructionsSymbols Identification

> Relays and Modules > Relays and Modules - Cooling System > Radiator Cooling Fan Control Module > Component Information > Diagrams > Diagram Information and

Instructions > How to Use Wiring Diagrams > Page 28

90S, CS V6-2.8L (AAH) (1994)

Symbols (Part 1 Of 2)

Symbols (Part 2 Of 2)

> Relays and Modules > Relays and Modules - Cooling System > Radiator Cooling Fan Control Module > Component Information > Diagrams > Diagram Information and Instructions > How to Use Wiring Diagrams > Page 29

Standard Circuit/Terminal Designations

> Relays and Modules > Relays and Modules - Cooling System > Radiator Cooling Fan Control Module > Component Information > Diagrams > Diagnostic Aids > Troubleshooting Basics > Procedure

Radiator Cooling Fan Control Module: Diagnostic AidsProcedure
Verify The Complaint:

Check the complaint. Try to understand the problem. If possible, let the driver show you what happens. Check all functions of the system and note thesymptoms before starting any testing or disassembly.

Analyze The Problem:

Identify the part of the electrical system that is most likely to be causing the problem. Find the Circuit Section in the manual that applies to that part ofthe system. Find the wiring diagram that applies to the vehicle. By following the circuit from a ground (GND) back to the power source, get anunderstanding of how the circuit works.

Find The Problem:

You will find the problem if you follow a simple and logical step-by-step procedure. Test portions of the circuit one at a time, starting with he area orcomponent most likely to be malfunctioning. Test first at points that you can reach most easily.

Repair The Problem:

When you find the cause of the problem, make the repair. Use appropriate tools and procedures.

Check The Results:

Be sure it works. Check the functions of all parts of the circuit that you worked on.

Working On The Electrical System:

A test light or a multimeter can be very helpful for testing circuits. See Tools and Equipment for more information on test equipment.Current flow is logical, always moving from the highest potential at the Voltage source (+) toward the lowest potential at ground (-). Using a wiringdiagram to trace a circuit, you should start with the ground (GND) and then follow the wires back to the source of power.

To Troubleshoot A Circuit:

1. Inspect all connections, especially grounds (GND). Make sure they are clean, tight and corrosion-free.2. Check the fuses.

Repeated fuse failures are the sign of a malfunctioning wire, a failed component, or a short to ground (GND) somewhere in the circuit.NOTE:

3. Check for Voltage reaching particular components or points in the circuit.4. Check continuity between points to look for breaks in the circuit (open circuit).5. Check Voltage drop at connections, especially ground (GND) connections.

> Relays and Modules > Relays and Modules - Cooling System > Radiator Cooling Fan Control Module > Component Information > Diagrams > Diagnostic Aids > Troubleshooting Basics > Procedure > Page 33

Radiator Cooling Fan Control Module: Diagnostic AidsBasic Electricity

Electricity

Electricity is defined by three basic elements: Voltage, Current and Resistance.

Voltage

Voltage is a measure of electromotive force, sometimes referred to as electrical "pressure". It can be described as the difference in potential(potential for the flow of electricity) between any two points in a circuit.

12 Volts

A typical automobile battery, for example, has a difference in potential of about between the positive (+) terminal and the negative (-)terminal.

The basic units of electrical potential are (V). Very low Voltages are expressed as (mV).Volts millivolts

= ; = 1 V 1000 mV 1 mV 0.001 V

Current

Current is the term describing the flow of electricity through a conductor. In a complete circuit, potential (Voltage) will cause current to flow frompositive (+) to negative (-).

The basic units of current flow are or (A). Small amounts of current flow are often measured in (mA).amperes amps milliamps

= ; = 1 A 1000 mA 1 mA 0.001 A

Resistance

Resistance resists or opposes the flow of electricity. Conductors are made from materials of low resistance that allow electricity to flow easily.Insulators are materials of very high resistance that inhibit the low of electricity.

The basic unit of resistance is the . High resistance values are often expressed as .Ohm Kilo ohms (K ohm)

= 1K ohm 1000 ohm

Resistance vs. Current Flow

1 Volt 1 am

The basic rule of electricity (Ohm's Law) states that one unit of force () is required for one unit of current () to flow against one unit ofresistance (). From Ohm's Law, we also know that:1 Ohm

Voltage = Current x Resistance

When Voltage is approximately constant, as in an automobile electrical system, current and resistance affect each other. As resistance increases,there will be less current flow. And lower resistance will permit higher current flow.

Higher resistance = lower current flow

Example: Corrosion on a headlight connector (higher resistance) causes the light to be dim (lower current flow).

Lower resistance = higher current flow

Example: A damaged wire shorted to ground (lower resistance) overloads circuit capacity (higher current flow) and blows a fuse. (GND)

Definition of a Circuit

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Troubleshooting Basics > Procedure > Page 34

90S, CS V6-2.8L (AAH) (1994)

A Complete Circuit

Four things are required for current to flow in any electrical circuit, and for that circuit, and for that circuit to function as intended:-

Power Source (Voltage)

- Conductors (wires, printed circuits, etc.)

- Load or Consumer (a user of electrical power)

- Complete Circuit (a connection to ground)

Open Circuits

An open circuit is an incomplete circuit. An open circuit occurs when some kind of malfunction interrupts the circuit path and prevents currentflow. Some common causes of open circuits are:-

Broken wire

- Loose or disconnected connector

- Loose or damaged connector terminal

- Corrosion

- Malfunctioning fuse or component

Test for an open circuit by checking continuity using an Ohmmeter (multimeter), or by checking for Voltage at various points of the circuit using atest light or Voltmeter (multimeter). See Checking Wiring and Components.

Short Circuits

A short circuit is an unintended complete circuit. A short circuit occurs when some kind of malfunction causes current flow to follow the wrongpath.

A short circuit to ground (GND) (grounded circuit) may prevent Voltage from reaching a component. If Voltage is shorted directly to ground(GND), bypassing any load, the unrestricted current flow will damage fuses wires or components. Some common causes of short circuits are:-Damaged wire or wiring harness- Malfunctioning insulation

- Internally damaged component

- Incorrect connection

Test for a short circuit to ground (GND) using a multimeter or a test light to indicate circuit malfunctions and abnormal current flow paths. SeeChecking for Short Circuit to Ground (GND).

> Relays and Modules > Relays and Modules - Cooling System > Radiator Cooling Fan Control Module > Component Information > Diagrams > Diagnostic Aids > Troubleshooting Basics > Procedure > Page 35

Radiator Cooling Fan Control Module: Diagnostic AidsChecking For Voltage
Voltage

Checking for Voltage confirms that the circuit is uninterrupted between the Voltage source and the test point.

> Relays and Modules > Relays and Modules - Cooling System > Radiator Cooling Fan Control Module > Component Information > Diagrams > Diagnostic Aids >

Troubleshooting Basics > Procedure > Page 36

90S, CS V6-2.8L (AAH) (1994)

Testing For Voltage

This example illustrates troubleshooting the high-speed circuit for the radiator cooling fan.

Voltage:

If the test light or multimeter indicates Voltage potential, then the circuit between the Voltage source and terminal 1 of the fan connector is OK.

NO Voltage:

Power is not reaching the fan connector. The fan is probably OK. Look for a malfunction somewhere between the Voltage source and the fanconnector. (Example: Check for Voltage reaching terminal E87La of the fuse/relay panel)

CAUTION:

Direct contact with meter probes at the connector terminals can easily damage the small contacts, causing poor connections and risking futureintermittent malfunctions.Special Tools include adapters for making test connections safely and preventing connector damage. See Tools and Equipment.

> Relays and Modules > Relays and Modules - Cooling System > Radiator Cooling Fan Control Module > Component Information > Diagrams > Diagnostic Aids > Troubleshooting Basics > Procedure > Page 37

Radiator Cooling Fan Control Module: Diagnostic AidsChecking Ground Connection
Ground Connection

Checking ground (GND) connections as shown confirms that the circuit is complete that the necessary path to ground (GND) is uninterrupted andcurrent can flow in the circuit. The examples illustrate two methods of troubleshooting a high-speed circuit for the radiator cooling fan. Testing with an ohmmeter and testing with atest light or voltmeter.

Testing With An LED Test Light Or Voltmeter (Multimeter)

> Relays and Modules > Relays and Modules - Cooling System > Radiator Cooling Fan Control Module > Component Information > Diagrams > Diagnostic Aids >

Troubleshooting Basics > Procedure > Page 38

90S, CS V6-2.8L (AAH) (1994)

> Relays and Modules > Relays and Modules - Cooling System > Radiator Cooling Fan Control Module > Component Information > Diagrams > Diagnostic Aids >

Troubleshooting Basics > Procedure > Page 39

90S, CS V6-2.8L (AAH) (1994)

Testing For Ground Connection

Voltage:

If the test light or multimeter indicates Voltage, then there is potential for current flow between the known Voltage source and ground (GND) atthe test point. The ground (GND) side of the circuit, between terminal 3 of the fan connector and battery negative (-), is OK.

NO Voltage:

The test point is not providing a path that completes the circuit to ground (GND). The fan is probably OK. Look for a malfunction somewhere inthe wiring between the fan connector and chassis ground (GND). Also check the mechanical ground connection at the chassis (body).

Testing With An Ohmmeter (Multimeter):

> Relays and Modules > Relays and Modules - Cooling System > Radiator Cooling Fan Control Module > Component Information > Diagrams > Diagnostic Aids >

Troubleshooting Basics > Procedure > Page 40

90S, CS V6-2.8L (AAH) (1994)

Testing For Ground Connection

Continuity (approximately 0 Ohm):

Little or no resistance indicates that there is a continuous conductive path between the two test points - the circuit's ground (GND) path betweenterminal 3 and battery negative (-) is OK.

No Continuity:

There is resistance to current flow in the ground (GND) side of the circuit. The fan is probably OK. Look for a malfunction somewhere in thewiring between the fan connector and chassis ground (GND). Also check the mechanical ground (GND) connection at the chassis (body).

CAUTION:

Direct contact with meter probes at the connector terminals can easily damage the small contacts, causing poor connections and risking futureintermittent malfunctions.Special Tools include adapters for making test connections safely and preventing connector damage. See Tools and Equipment.

> Relays and Modules > Relays and Modules - Cooling System > Radiator Cooling Fan Control Module > Component Information > Diagrams > Diagnostic Aids > Troubleshooting Basics > Procedure > Page 41

Radiator Cooling Fan Control Module: Diagnostic AidsChecking Wiring and Components

Checking Resistance Or Continuity

Checking a portion of the wiring harness or a component as shown indicates whether or not there is a continuous conductive path - whether currentcan flow between the two test points. The example illustrates troubleshooting the Close Throttle Position switch and the Wide Open ThrottlePosition switch in the fuel injection system.

CAUTION:

Resistance measurements and continuity checks must always be made with all power to the circuit or component switched OFF. When testingcontinuity in a circuit that is always powered (fuse/relay panel "30" circuit for example) disconnect the battery before testing. Always use a digital (low current) meter. An ohmmeter, or the Ohms scale of a multimeter, measures resistance by passing a small amount ofcurrent through the circuit or component being checked. Improper testing may damage sensitive electronic components. Direct contact with meter probes at the connector terminals can easily damage the small contacts, causing poor connections and risking futureintermittent malfunctions.Special Tools include adapters for making test connections safely and preventing connector damage. See Tools and Equipment.

Example 1: Checking A Closed Throttle Position Switch

> Relays and Modules > Relays and Modules - Cooling System > Radiator Cooling Fan Control Module > Component Information > Diagrams > Diagnostic Aids >

Troubleshooting Basics > Procedure > Page 42

90S, CS V6-2.8L (AAH) (1994)

Testing For Resistance Or Continuity

Continuity (approximately 0 ohm):

Little or no resistance indicates that there is a continuous conductive path between the two test points. As shown, this is correct for the normallyClosed Throttle Position switch in the Closed Throttle Position (switch not actuated). Also check that the switch opens (no continuity) whenactuated by the throttle.

No Continuity:

There is resistance to current flow through the switch. In the example, this indicates that the normally Closed Throttle Position switch or the wiresbetween it and the connector (t3) are malfunctioning.

Example 2: Checking A Wide Open Throttle Position Switch

Testing For Resistance Or Continuity

Continuity (approximately 0 ohm):

Little or no resistance indicates that there is a continuous conductive path between the two test points. In the example, this indicates that thenormally Wide Open Throttle Position switch is malfunctioning.

No Continuity:

There is no connection-an open circuit. As shown, this is correct for the normally Wide Open Throttle Position switch. Also check that the switchcloses, completing the circuit, when actuated by the Wide Open Throttle Position switch.

> Relays and Modules > Relays and Modules - Cooling System > Radiator Cooling Fan Control Module > Component Information > Diagrams > Diagnostic Aids > Troubleshooting Basics > Procedure > Page 43

Radiator Cooling Fan Control Module: Diagnostic AidsChecking For Short Circuit to Ground
Short Circuits

(GND)

Checking the circuit as shown will detect circuit malfunctions that are providing an unintended current flow path to ground . Covered here aretwo methods of troubleshooting a short circuit to ground (GND). Testing with an ohmmeter and testing with a test light or voltmeter.

CAUTION:

Always use a digital (low current) meter. An ohmmeter, or the Ohms scale of a multimeter, measures resistance by passing a small amount of currentthrough the circuit or component being checked. Improper testing may damage sensitive electronic components.Direct contact with meter probes at the connector terminals can easily damage the small contacts, causing poor connections and risking futureintermittent malfunctions. Special Tools include adapters for making test connections safely and preventing connector damage. See Tools andEquipment.

Testing With An Ohmmeter (Multimeter):

> Relays and Modules > Relays and Modules - Cooling System > Radiator Cooling Fan Control Module > Component Information > Diagrams > Diagnostic Aids >

Troubleshooting Basics > Procedure > Page 44

90S, CS V6-2.8L (AAH) (1994)

Testing For Short Circuit To Ground

The example used here is a short that is causing a blown fuse in the circuit powering the license plate lights and the glove compartment light.

Step 1 - Remove the fuse

Step 2 - Disconnect the load (powered components) to eliminate the circuit's normal path to ground (GND)Step 3 - Connect the Ohmmeter as illustrated

Continuity (approximately 0 ohm):

Little or no resistance indicates that there is a continuous conductive path between the isolated circuit and ground (GND), even though all thecircuit's normal ground (GND) paths are eliminated. There is a short - an unintentional connection to ground (GND) - somewhere in the circuit.

No Continuity:

The circuit's normal ground (GND) paths have been disconnected, and there is no other connection between the isolated circuit and ground (GND)- no short has been detected.

Testing With An LED Test Light Or Voltmeter (Multimeter)

> Relays and Modules > Relays and Modules - Cooling System > Radiator Cooling Fan Control Module > Component Information > Diagrams > Diagnostic Aids >

Troubleshooting Basics > Procedure > Page 45

90S, CS V6-2.8L (AAH) (1994)

Testing For Short Circuit To Ground

The example used here is a short that is causing a blown fuse in the circuit powering the license plate lights and the glove compartment light.

Step 1 - Remove the fuseStep 2 - Disconnect the load (powered components) to eliminate the circuit's normal path to ground (GND)Step 3 - Connect the test light or voltmeter as illustrated

Voltage:

If the test light or multimeter indicates Voltage, then there is a complete circuit - a connection to ground (GND) even though all the circuit'sNormal ground (GND) paths are eliminated. There is a short - an unintentional connection to ground (GND) - somewhere in the circuit.

NO Voltage:

There is not a complete circuit. The circuit's normal ground (GND) paths have been disconnected, and there is no other connection between theisolated circuit and ground (GND) - no short has been detected.

> Relays and Modules > Relays and Modules - Cooling System > Radiator Cooling Fan Control Module > Component Information > Diagrams > Diagnostic Aids > Troubleshooting Basics > Procedure > Page 46

Radiator Cooling Fan Control Module: Diagnostic AidsChecking For Voltage Drop

Voltage Drop Test

Checking Voltage drop across connections or components as shown will indicate whether there is abnormal resistance creating an additional loadin the circuit - consuming power and dropping the Voltage available to other parts of the circuit.

Voltage drop measurements can only be made when the circuit is powered and there is normal current flow.NOTE:

> Relays and Modules > Relays and Modules - Cooling System > Radiator Cooling Fan Control Module > Component Information > Diagrams > Diagnostic Aids >

Troubleshooting Basics > Procedure > Page 47

90S, CS V6-2.8L (AAH) (1994)

Testing For Voltage Drop

The example illustrates troubleshooting the back-up light switch. The switch is in the circuit to switch power to the back-up lights ON and OFF.When Reverse gear is selected and the switch is closed, it should have very little resistance and not be a consumer.

If dirt or corrosion on the switch contacts creates resistance, some of the available battery Voltage goes into overcoming that resistance. LessVoltage is available to light the back-up lights, and they will not be as bright.

An ohmmeter can measure resistance (or check continuity) only when the circuit is not powered, i.e. when there is almost no load.NOTE:

Low Voltage:

A low Voltage reading across the two switch contacts indicates almost no difference in potential. Resistance across the switch is low - most of thebattery Voltage is passing through the switch and is still available to power the lights.

High Voltage:

Any significant Voltage reading indicates a difference in potential across the switch contacts. Excessive resistance is loading the circuit, causing aVoltage Drop. Voltage is consumed overcoming the resistance of the switch, and less is left to power the lights.

Maximum allowable Voltage drops recommended by the Society of Automotive Engineers are:

0.0 Volt

0.1 Volt

0.1 Volt

0.2 Volt
for small wire connections for high-current connections (Example: fuel pump, headlights) for ground (GND) connections for high-current cables (Example: battery/starter cable) for switch or relay contacts0.3 Volt

> Relays and Modules > Relays and Modules - Cooling System > Radiator Cooling Fan Control Module > Component Information > Diagrams > Diagnostic Aids > Troubleshooting Basics > Page 48

Radiator Cooling Fan Control Module: Diagnostic AidsHandling Components and Connector
Harness Connectors

The harness connectors used throughout the vehicle are designed to positively lock into place.

Harness Connector

Typical wiring harness connector. Push on wire lock (arrow) and gently pull on connector to release.

To disconnect, pull only on the connector body. Never pull on the wires themselves.CAUTION:

Making Test Connections

Many electrical troubleshooting tests will require hooking up to wiring harness connectors, or socket connectors on electrical components. Testconnections made carelessly or without proper tools can easily damage the connectors, causing poor connections and future problems.

Alligator-clip Test Leads With Flat Connectors

To avoid connector damage, test connections to wiring harness connectors must be made using small, flat-blade terminals which will mate properlywith the connectors. The Special Tools recommended include special adapters which can be used to make test connections safely and preventconnector damage. See Tools and Equipment.All test connections to harness connectors should be made using the proper adapter or correct size flat connectors that will not deform the connectorcavities.

Wiring Harness Repairs

> Relays and Modules > Relays and Modules - Cooling System > Radiator Cooling Fan Control Module > Component Information > Diagrams > Diagnostic Aids >

Troubleshooting Basics > Page 49

90S, CS V6-2.8L (AAH) (1994)

W-Type Crimp Connection

When repairing wiring harnesses, use only high-quality electrical connectors suitable for use with electronic components.

Wire Crimping Pliers, For Making W-Type Crimps

> Relays and Modules > Relays and Modules - Cooling System > Radiator Cooling Fan Control Module > Component Information > Diagrams > Diagnostic Aids >

Troubleshooting Basics > Page 50

90S, CS V6-2.8L (AAH) (1994)

Wire Crimping Pliers, Not Suitable For W-Type Crimps

To make connections, use crimping pliers that make a "W"-type crimp. Only this type of crimp provides the necessary mechanical strength.Connector repair kits, connectors and the correct crimping pliers are available through your authorized dealer Parts Department.

Wiring Harness Repair Kit VAS 1978

Wire Harness Repair Kit, VAS 1978

Wiring Harness Repair Kit VAS 1978 was developed to simplify wiring harness repairs by using factory pre-crimped replacement wires thuselimination numerous repair kits and crimping fixtures. All of the tools and parts are conveniently located in one case and are easy to use. VAS 1978kit reduces the total repair steps needed to effect repair.

> Relays and Modules > Relays and Modules - Cooling System > Radiator Cooling Fan Control Module > Component Information > Diagrams > Diagnostic Aids > Tools and Equipment > LED Test Light

Radiator Cooling Fan Control Module: Diagnostic AidsLED Test Light

Test Light

A test light is an inexpensive tool used to perform many simple electrical tests that would otherwise require a multimeter. It lights to indicate whenthere is Voltage potential between any two test-points in a circuit.

With one probe contacting the battery negative (-) terminal or a known ground (GND) connection, the other probe can be used to check forVoltage at other points in the circuit. The test light will light when the test probe contacts a Voltage source, and current flows from the Voltagesource to ground (GND).

With one probe contacting a known source of Voltage, the other probe can be used to check for continuity to ground (GND) at other points in thecircuit. Current will flow and the test light will light when the test-point provides the known Voltage source with a path to ground (GND).

CAUTION:

A common test tight (with incandescent bulb) may no longer be used. The bulb's high current draw will damage sensitive electroniccomponents.

LED Test Light (US 1115)

LED Test Light

Used to check for Voltage reaching components or when searching for malfunctions in a circuit.

Voltage range: to DC3 48 Volts

NOTE

: This tool has been superseded by Special Tool VAG 1527B, LED Tester. (US 1115 is still considered an acceptable equivalent to VAG1527B).

LED Tester (VAG 1527B)

> Relays and Modules > Relays and Modules - Cooling System > Radiator Cooling Fan Control Module > Component Information > Diagrams > Diagnostic Aids > Tools and

Equipment > LED Test Light > Page 53

90S, CS V6-2.8L (AAH) (1994)

LED Test Light

Order Number: TAG 152 7B0 28 ZELTwo-pole Voltage tester with two LEDs (light emitting diodes), suitable for measuring from to DC or AC.3 48 Volts

When used to test DC circuits, the positive (+) or negative (-) LED will light, depending on polarity. When used to test AC circuits, both LEDswill light.

Supplied with banana clip and detachable probe-can be used directly with VAG 1598 Test Box.

For troubleshooting all common electrical and electronic components in automobiles. Safe for testing electronic components and circuits becauseof extremely low current consumption ( maximum).1.5 mA

Voltage range: to (AC or DC)3 48 Volts

: This tool supersedes Special Tool US 1115 LED Test Light.NOTE

Making an LED Test Light

LED Test Light

A lower-cost alternative to buying an LED Test Light such as US 1115 or VAG 1527B is to make one, using parts available from most anyelectronics supply outlet.

Assemble the components as shown. Use needle nose pliers to hold the parts and to act as a heat dam while soldering. Insulate the connectionswith heat-shrinkable tubing or electrical tape.

PARTS:

1/4 watt, 330 ohm resistor

1. LED (1)2. (1)3. Alligator clips (2)4. Wire, Solder and Soldering Iron5. Heat-shrinkable tubing or electrical tape

> Relays and Modules > Relays and Modules - Cooling System > Radiator Cooling Fan Control Module > Component Information > Diagrams > Diagnostic Aids > Tools and Equipment > LED Test Light > Page 54

Radiator Cooling Fan Control Module: Diagnostic AidsMultimeter or Volt/Ohm Meter

Multimeter

(VOM)

A multimeter or Volt-Ohm Meter is used to measure Voltage, Resistance (Ohms) or Current (amps or milliamps). Two types of meters arein common use. The analog or swing-needle Volt-Ohm meter displays test values according to the position of a needle on the meter face. A digitalmultimeter displays test values as numbers. The meters shown here and recommended are digital multimeters.

Accuracy is an important consideration when choosing a meter. Analog or swing-needle Voltmeters are generally rated for accuracy as apercentage of full-scale on the meter face. A typical analog meter may be rated as accurate to 3% of full scale. Some analog meters offer 10-Voltand 50-Volt scales, with no range in between. For 12-Volt automotive electrical systems, this means testing on the 50-Volt scale, with acorresponding decrease in accuracy. On a 50-Volt scale, 3% accuracy is equal to 1.5 Volts. While still useful for testing circuits such as lightsand horns, analog meters may not be accurate enough for use where precise measurements are required.

(DVOM)

Digital multimeters or Digital Volt-Ohm Meter are preferred for precise measurement and for electronics work because most digitalmultimeters are more accurate then most analog meters. Another advantage of digital multimeters is that they are less likely to be misread, sincethere is no needle position to be misinterpreted or distorted by reading at an angle.

Perhaps the most important consideration is input impedance how much of a load the meter places on the circuit being tested. Meters with lowinput impedance place a greater load on the circuit because they allow more current flow through the meter. This can exceed design limits and bedamaging to sensitive electronic components.

Most digital multimeters have very high input impedance 10 megohms (10,000,000 ohm) or higher-and make their measurements while allowingvery little current flow through the meter. The meter itself is not a load in the circuit, and does not induce damaging current flow.

Digital Multimeter Kit, (US 1119, VAG 1526)

Digital Multimeter Kit

Order Number: TU1 119 000 00 KTM Used for monitoring electronic engine controls (Example: setting/checking the idle speed control system) and for general electricaltroubleshooting.

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90S, CS V6-2.8L (AAH) (1994)

NOTE: (R)

This tool has been superseded by the Fluke 83 Digital Multimeter. (US 1119 or VAG 1526 are still considered acceptableequivalents).

Fluke 83(R) Digital Multimeter

Digital Multimeter

Order Number: TFL UKE 830 00 RSE Used for monitoring electronic engine controls (Example: setting/checking the idle speed control system) and for general electricaltroubleshooting.-

10 Megohm input impedance

- 0.3% DC Voltage accuracy

- Fully overload-protected

This tool supersedes Special Tool US 1119 digital multimeter kit.NOTE:

> Relays and Modules > Relays and Modules - Cooling System > Radiator Cooling Fan Control Module > Component Information > Diagrams > Diagnostic Aids > Tools and Equipment > LED Test Light > Page 56

Radiator Cooling Fan Control Module: Diagnostic AidsTest Kits

Adaptor Kit (VW 1594)

Adaptor Kit

CAUTION:

Test connections made carelessly or without proper tools can damage harness connectors, causing poor connections and futureproblems.

Test Box (VAG 1598)

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90S, CS V6-2.8L (AAH) (1994)

Order Number: TV1 594 400 97 KTMUsed to connect electrical measuring equipment to various harness connectors in the electrical system.

Test Box

Order Number: WAG 159 800 00 VOAUsed to perform static and dynamic tests of electrical and electronic systems without damaging miniature contacts, especially where limited accessto connectors makes testing difficult.

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90S, CS V6-2.8L (AAH) (1994)

Tester (VAG 1466)

Tester

Used to systematically troubleshoot electrical circuits.

> Relays and Modules > Relays and Modules - Cooling System > Radiator Cooling Fan Control Module > Component Information > Diagrams > Diagnostic Aids > Tools and Equipment > LED Test Light > Page 59

Radiator Cooling Fan Control Module: Diagnostic AidsComputer Memory Saver

Computer Memory Saver

Snap-On Computer Memory Saver

Used on vehicles with theft-protected radios to prevent the radio from electronically locking when battery power is disconnected. Use of this tooleliminates the need to reactivate the radio (reenter the correct code) after reconnecting battery power.

WARNING:

Always separate the airbag Voltage supply connector before using a computer memory saver. Failure to do so may result in accidentalactivation of the airbag. For more information rewfert to the Airbag wiring.

Home-Made Tool

Home-made Computer Memory Saver

> Relays and Modules > Relays and Modules - Cooling System > Radiator Cooling Fan Control Module Relay > Component Information > Diagrams > Diagram Information and Instructions > How to Use Wiring Diagrams

Radiator Cooling Fan Control Module Relay: Diagram Information and InstructionsHow to Use Wiring Diagrams

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90S, CS V6-2.8L (AAH) (1994)

Wiring Diagram Layout

Wiring Diagram Details

1 Arrow

Indicates wiring circuit is continued on the previous and/or next diagram section.

2 Fuse Designation

Example: S15 = Fuse number 15, 10 amps, in fuse/relay panel.

3 Test Points On Fuse/Relay Panel
4 Test Points Used During Troubleshooting

Numbers in black circles may be found in a regular wiring diagram or in a wiring diagram included with troubleshooting.

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90S, CS V6-2.8L (AAH) (1994)

5 Wire Cross-section Size And Wire Color Code

Wire size is in mmsq, for wire size conversion to American Wire Gauge (AWG), see Wire Size Conversion Chart. Wire color codes are explained in Wire Color Code Identification.

6 Component Designation (code)

Use diagram article to identify the component code.For example: G39 = Heated Oxygen Sensor

7 Internal Connections (thin lines)

These connections are not always wires. Internal connections are current carrying and are listed to allow tracing of current flow insidecomponents and wiring harnesses.

8 Wire Harness Ground Connection

Locations of ground connections are indicated in the diagram article.

9 Relay/Control Module Connectors On Fuse/Relay Panel

Shows the individual terminals in a multi-point connector. Example: 4/304 = Contact 4 of the relay/control module socket on the relay panel or relay carrier 30 = Terminal 30 (B+) on relay/control module

10 Relay Location Number

Indicates relay location on fuse/relay panel.

11 Fuse/Relay Panel Connectors

Shows wiring of multi-point or single connectors on fuse/relay panel.Example: G1/10 = Multi-point connector G1, terminal 10

12 Terminal Designation

Designation which appears on actual component and/or terminal number of a multi-point connector.

13 Wire Continuation (Current Track Number)

Number in frame indicates current track where wire is continued.

14 Continuation of Internal Connections

Letters indicate where connection continues on the previous and/or next diagram section.

15 Component Symbols

Example component symbols are illustrated in Symbols Identification

16 Wiring Harness Splice Connection

Locations of splice connections are indicated in the diagram article.

17 Arrow

Indicates component is continued on the previous and/or next diagram section.

18 Component Designation (code) Without Component Symbol

Indicates circuit continues to a component that is on a different system diagram. The component is identified by its component designation(code).Example: J60 = Automatic Transmission RelayIf this circuit was needed it would be necessary to go to the Automatic Transmission Wiring Diagram and locate the Automatic TransmissionRelay (J60).

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Radiator Cooling Fan Control Module Relay: Diagram Information and InstructionsWire Color Code Identification

Color Codes

WS

- White

SW

- Black

RO

- Red

BR

- Brown

GN

- Green

BL

- Blue

GR

- Gray

LI

- Violet

GE

- Yellow

OR

- Orange

Combined codes indicate a multi-colored wire.Example: The code R/G indicates a red wire with a green tracer strip.

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Radiator Cooling Fan Control Module Relay: Diagram Information and InstructionsWire Size Conversion Chart

Wire Size

The wiring diagrams in this manual identify wires by their metric wire size. Metric wire sizes indicate cross-sectional area in square millimeter . The table below lists metric wire sizes and their equivalents in American Wire Gauge sizes.(mm sq.) (AWG)

Metric size American Wire Gauge

(mm sq.) (AWG)

0.35 22

0.5 20

0.75 18

1.0 16

1.5 14

2.5 12

4.0 10

6.0 8

16.0 4

25.0 2

35.0 2

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Radiator Cooling Fan Control Module Relay: Diagram Information and InstructionsConnector Information

Connector Connector

Designation Type

T1 Single-point

T2 2-point

T3 3-point

T4 4-point

T6 6-point

T8 8-point

T10 10-point

T12 12-point

T26 26-point
Each connector has a unique number. Example: T6, T6a and T6b are three different 6-point connectors.
Wiring diagrams usually also identify a particular connector terminal.

3-Point Connector

Example: T3a/2 is terminal two of connector T3a.

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Radiator Cooling Fan Control Module Relay: Diagram Information and InstructionsSymbols Identification

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90S, CS V6-2.8L (AAH) (1994)

Symbols (Part 1 Of 2)

Symbols (Part 2 Of 2)

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Page 72

Standard Circuit/Terminal Designations

> Relays and Modules > Relays and Modules - Cooling System > Radiator Cooling Fan Control Module Relay > Component Information > Diagrams > Diagnostic Aids > Troubleshooting Basics > Procedure

Radiator Cooling Fan Control Module Relay: Diagnostic AidsProcedure
Verify The Complaint:

Check the complaint. Try to understand the problem. If possible, let the driver show you what happens. Check all functions of the system and note thesymptoms before starting any testing or disassembly.

Analyze The Problem:

Identify the part of the electrical system that is most likely to be causing the problem. Find the Circuit Section in the manual that applies to that part ofthe system. Find the wiring diagram that applies to the vehicle. By following the circuit from a ground (GND) back to the power source, get anunderstanding of how the circuit works.

Find The Problem:

You will find the problem if you follow a simple and logical step-by-step procedure. Test portions of the circuit one at a time, starting with he area orcomponent most likely to be malfunctioning. Test first at points that you can reach most easily.

Repair The Problem:

When you find the cause of the problem, make the repair. Use appropriate tools and procedures.

Check The Results:

Be sure it works. Check the functions of all parts of the circuit that you worked on.

Working On The Electrical System:

A test light or a multimeter can be very helpful for testing circuits. See Tools and Equipment for more information on test equipment.Current flow is logical, always moving from the highest potential at the Voltage source (+) toward the lowest potential at ground (-). Using a wiringdiagram to trace a circuit, you should start with the ground (GND) and then follow the wires back to the source of power.

To Troubleshoot A Circuit:

1. Inspect all connections, especially grounds (GND). Make sure they are clean, tight and corrosion-free.2. Check the fuses.

Repeated fuse failures are the sign of a malfunctioning wire, a failed component, or a short to ground (GND) somewhere in the circuit.NOTE:

3. Check for Voltage reaching particular components or points in the circuit.4. Check continuity between points to look for breaks in the circuit (open circuit).5. Check Voltage drop at connections, especially ground (GND) connections.